Mercury Decision: ‘Virtually All’ Mercury In Ocean Fish Is ‘From Natural Sources’

On Friday, when the scales of justice swung in California’s landmark mercury-in-tuna court case, they hit some cherished environmental dogma squarely in the face. Green groups have long held that the trace amounts of methylmercury in fish (tuna being the most oft-cited example) are the result of pollution caused by human beings. In fact, most of the environmental campaigns that hype the theoretical health risks of eating fish (click here, here, here, and here for examples) are really aimed at changing clean-air laws. Fish are just a stalking horse, used to whip up fear about mercury in the environment. But now, at least in California, the truth has become a matter of law — that the vast majority of these tiny traces of mercury are as natural as the earth itself.

Don’t have time to read the whole 118-page court decision? Don’t worry. We’ve pulled out some important observations that should help re-shape the way Americans think about mercury: Page 60: The Judge ruled that “there is no dispute that most of the methylmercury in the ocean exists completely independently of human activity.” Dr. Francois Morel, a noted Princeton University environmental scientist, testified that the percentage of mercury in tuna that originates from human sources “is either zero or 1.5 per cent.”

Page 61: University of Connecticut marine scientist Dr. William Fitzgerald, the court wrote, testified that he “knows of no peer-reviewed study that has found an increase in methylmercury in ocean fish during the time period when atmospheric mercury levels have increased.” And the defense “presented scientific studies that show there has been no increase in the amount of methylmercury in ocean fish during the past 100 years.

Page 65: The court heard about a scientific study showing that that the mercury levels in tuna caught in 1998 “were nearly identical to (and in fact slightly less than)” the levels in fish caught back in 1971. This supports the court’s conclusion that “there is almost no anthropogenic [human-derived] methylmercury in the ocean.

Page 76: “There is evidence,” the court wrote, that mercury begins its natural journey up the food chain “in deep ocean hydrothermic vents … If hydrothermic vents are the source of methylmercury, then 100 percent of methylmercury in the ocean is naturally occurring.” In fact, according to Dr. Fitzgerald, “deep ocean vents produce enough methylmercury to account for about four times the amount of methylmercury that bioaccumulates in ocean fish each year.

Page 116: The final nail in a giant scare campaign: The court declares that “methylmercury in fish, including tuna, does not respond to human pollution, and is a natural part of the product’s environment.

Stay tuned for the rest of the week as we continue to explore how this remarkable legal decision has exposed the hollow rhetoric and unscientific hype of mercury fear campaigns.

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